We all know the adage for losing weight: eat less, exercise more.

We all know the adage for losing weight: eat less, exercise more. It turns out that advice isn’t just an oversimplification, it could be the reason why you’re actually gaining weight. In a conversation with David Perlmutter, Dr. David Ludwig – endocrinologist, professor of nutrition at Harvard School of Public Health, and author of the bestseller Always Hungry? – explored this counterintuitive phenomenon.

When we cut back on calories, Ludwig explained, the combination of hunger, energy expenditure, and metabolism crashes can lead to weight gain. “It’s like trying to treat fever with a cold shower,” he said. Just as that tactic wouldn’t actually lower your body temperature, calorie deprivation doesn’t successfully lower body weight for most people over the long term. On the contrary, when we put fewer calories into our system, it sends a message to our brain that food is scarce. Our hunter-gatherer instincts kick in, and our brain inspires a search for food by making us feel hungry.

The calorie balance approach is deeply embedded in American culture, and Dr. Ludwig argues it’s time for revision. “We’ve been using the same approach to obesity that was initially formulated when bloodletting was a dominant treatment for chronic diseases. Despite a century of elaborate behavioral methods and psychological approaches to help people do something very simple, eat less and move more, what do we know about standard obesity treatment? That it fails.”

Always Hungry? begins with a historical anecdote to illustrate his point. In 1905, William Taft was prescribed a low-calorie, low-fat diet and an exercise regimen to combat his weight. Instead of losing weight, he reported a constant hunger, and weighed in 40 pounds heavier when inaugurated as president three years later. This result is consistent with today’s findings when similar tactics are used to battle obesity.  While people might lose weight in the short term, their bodies typically “fight back” and regain the same amount of weight that was lost – sometimes even more – within a matter of years.

If we can’t rely on the old method of “eat less, exercise more,” how do we go about losing those extra pounds? Ironically, eating enough food may be the answer. “Hunger decreases, cravings vanish. Your energy expenditure picks up and weight loss occurs with, rather than against, your body’s cooperation,” Ludwig explains. If you can make your brain realize there’s no famine and that calories aren’t in short supply, then you’ll be more likely to reach a healthy weight without spending hours on the elliptical.